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Initiation and propagation of buckles in pipelines

1986; Elsevier BV; Volume: 22; Issue: 9 Linguagem: Inglês

10.1016/0020-7683(86)90032-6

1879-2146

Tomasz Wierzbicki, Shankar Bhat,

Fluid Dynamics Simulations and Interactions

Simple closed-form solutions are derived for the pressure necessary to initiate and propagate the buckle down the tube. The calculations are performed assuming that the dominant effect on the plastic energy dissipation has the circumferential bending mode. Using a rigid-plastic material idealization a simple moving hinge model which describes the deformation of a ring into a "dumbbell" shape is proposed. Strain-hardening effects are taken into account in an approximate way. The propagation pressure Pp is shown to be controlled by the thickness to diameter ratio of the shell and the ratio of the work-hardening modulus to the flow stress of the material. The resulting analytical solution for Pp is compared with the experimental results of Kyriakides et al. and the previous analytical solution due to Palmer and Martin. The solution for the initiation pressure PI is derived on the basis of the same structural model in conjunction with a new conceptual model for buckle initiation. The derived solutions for both Pp and PI are shown to correlate well with the experimental results recently reported in the literature.